The present invention relates to a permeable, more particularly gas/air pervious blocking layer composite with adsorbent and to use thereof.
More particularly, the present invention relates to an adsorptive filtering material, more particularly a blocking layer composite, as classified in the preamble of claim 1, that is useful in particular for the production of protective materials of any kind (such as, for example, protective suits, protective gloves, protective footwear and other protective apparel pieces and also protective coverings, for example for ambulance services, tents, sleeping bags and the like) and also for the production of filters and filtering materials and thus not only for the military but also the civilian sector, more particularly for NBC deployment.
The present invention further relates to the process for producing the adsorptive filtering material of the invention.
The present invention further relates to protective materials as such, that include the adsorptive filtering material of the present invention or are produced using the adsorptive filtering material of the present invention. The present invention also relates to filters and filtering materials as such, that include the adsorptive filtering material of the present invention or are produced using the adsorptive filtering material of the present invention.
The present invention further relates to the use of this adsorptive filtering material, more particularly blocking layer composite, in the aforementioned protective materials and in the above-described filters and filtering materials and also to the aforementioned protective materials and the aforementioned filters and filtering materials themselves.
There are a whole series of molecular entities which are absorbed by the skin and lead to serious physical noxae. Examples include the vesiccatory mustard gas (Yellow Cross) and the nerve gas sarin. People likely to come into contact with such poisons must wear a suitable protective apparel or be protected against these poisons by suitable protective materials.
Known for this purpose are for example air and water vapor impervious protective suits which are equipped with a rubber layer impervious to chemical poisons. The disadvantage here is that these suits very quickly lead to a buildup of heat, since they are air and water vapor impervious. Disadvantages here are the nonexistent breathability and also the nonexistent exchange of air.
The prior art additionally includes such protective suits as are constructed to be air impervious yet water vapor pervious/breathable. Protective suits of this kind generally include a membrane which acts as an air impervious yet water vapor pervious/breathable blocking layer and which may optionally be supplemented on its inside surface by an adsorbent (adsorptive filtering material) in order that adequate protection may be continued to be ensured in the event of any damage to the membrane. However, protective suit systems of this kind are not always able—particularly not under deployment conditions involving physical exertion—to ensure adequate breathability, so that wearing comfort is occasionally impaired as a consequence of the lack of air exchange.
Protective suits against chemical warfare agents, which are conceived for prolonged deployment under a variety of conditions, however, must not cause the wearer to suffer any heat buildup. Therefore, air and water vapor pervious protective suits are known for this purpose because they offer the highest wearing comfort.
The air pervious, permeable protective suits possess an adsorptive filtering layer with activated carbon, which binds the chemical poisons very durably, so that even strongly contaminated suits do not pose any danger to the wearer. The great advantage of systems of this kind is that the activated carbon is accessible on the inside surface as well as the outside surface, so that poisons which have succeeded in penetrating at damaged or otherwise nontight locations can be very rapidly adsorbed. Under extreme conditions, more particularly when a drop of a thickened poisonous or warfare agent material lands from a considerable height on the protective suit material and strikes through to the activated carbon, the layer of activated carbon can be locally overtaxed.
The adsorptive layer in the above-described, air pervious, permeable protective suits can be engineered such that, for example, either particles, more particularly granules or spherules, of activated carbon which are on average up to about 2.0 mm in size are bound to small accumulations of adhesive which have been printed onto a textile backing material, or alternatively that a reticulated polyurethane foam impregnated with a carbon paste of binder and activated carbon is used as adsorptive layer, in which case the adsorptive layer is generally supplemented by an outer (i.e., a covering material) and the wearer-facing inside surface is in turn covered by a lightweight textile material.
However, the prior art further includes composites comprising an activated carbon fiber fabric, for example a woven or nonwoven activated carbon fiber fabric (cf. for example WO 94/01198 A1 or its descendant EP 0 649 332 B1 or EP 0 230 097 A2).
This is because, owing to its highly non-specific adsorptive properties, activated carbon is the most widely used adsorbent. Activated carbon is generally obtained by carbonization and subsequent activation of carbonaceous starting compounds, preferably carbonaceous starting compounds which lead to economically sensible yields (cf. for example H. v. Kienle and E. Bäder, “Aktivkohle and ihre industrielle Anwendung”, Enke Verlag Stuttgart, 1980).